The present invention relates to an image forming apparatus using an electrophotographic type process and a process cartridge and a developer supply unit detachably mountable to an image forming apparatus.
Here, the electrophotographic image forming apparatus forms an image on a recording material through an electrophotographic image-formation-type process. Examples of electrophotographic image forming apparatus include an electrophotographic copying machine, an electrophotographic printer (laser beam printer, LED printer or the like), a facsimile machine and a word processor.
The above-described process cartridge contains as a unit an electrophotographic photosensitive member and a charging means, a developing means or a cleaning means in the form of a cartridge that is detachably mountable to a main assembly of an image forming apparatus. The process cartridge may contain an electrophotographic photosensitive member and at least one of a charging means, a developing means and a cleaning means in the form of a cartridge which is detachably mountably to a main assembly of an image forming apparatus. The process cartridge may contain an electrophotographic photosensitive member and at least developing means in the form of a cartridge that is detachably mountably to a main assembly of an image forming apparatus.
With a process-cartridge-type apparatus, the servicing or maintenance operations can be in effect carried out by the users, so that the operativity is significantly improved, and therefore, the process cartridge type is widely used in the electrophotographic field.
Recently, a toner-supply type, process-cartridge-type apparatus has been proposed with which the advantages of the process cartridge and the advantages of the toner-supply-type apparatus can be both enjoyed.
In such a system, the process cartridge comprises at least a photosensitive drum (electrophotographic photosensitive member), charging means for electrically charging the photosensitive drum, developing means for visualizing an electrostatic latent image formed on the photosensitive drum with toner, and a developer supply unit for metering the toner to the developing means (toner supply unit).
With the use of such a toner-supply-type process cartridge with the electrophotographic image forming apparatus, the maintenance and usability are improved, and the running cost can be reduced.
However, the toner-supply-type, process-cartridge, type apparatus in which the process cartridge and the toner supply unit are separable from each other involves the following problems.
The service life of the process cartridge which is integral with a toner bottle containing the supply toner, can be easily detected since the amount of the toner filled therein is known. However, in the system wherein the toner bottle of the toner supply unit is separable from the process cartridge, an additional means for detecting the service life is required.
Usually, the service lives of the process cartridge and toner supply unit detachably mountable to the main assembly are different, as follows:
Developer supply unit lifetimexe2x89xa6process cartridge lifetime
In other words, a plurality of developer supply units are used with one process cartridge, in most cases.
Therefore, it is necessary to detect the service lives of the developer supply unit and the process cartridge.
Accordingly, it is a principal object of the present invention to provide an image forming apparatus in which the end of the service life of a process unit detachably mountable to the image forming apparatus can be correctly detected.
It is another object of the present invention to provide an image forming apparatus in which information relating to the apparatus can be given to the user.
It is a further object of the present invention to provide an image forming apparatus, comprising:
an image bearing member;
developing means for developing a latent image formed on the image bearing member, the image bearing member and the developing means being detachably mountable to the apparatus as a process unit;
a developer supply unit for supplying a developer to the developing means, the developer supply unit being detachably mountable to the apparatus; and
a first memory mounted on the process unit, wherein the first memory stores information relating to the developer supply unit.
It is a further object of the present invention to provide a process unit detachably mountable to an image forming apparatus, comprising:
an image bearing member;
a developing means for developing a latent image formed on the image bearing member; and
a memory for storing information, wherein the memory is detachably mountable to the apparatus and stores information relating to a developer supply unit for supplying developer to the developing means.